Heat exchanger



April 28, 1931. J. A. POTTER 1,803,035

HEAT EXCHANGER Filed June 30, 1930 VIH- Il |l l n! pv' peoooQoQooo/32\Qoooooooooo/35 INVENTOR John H. Potter* BY @15M ATTORNEY baillebetween. the tubes Patented Apr. 28, 1931 UNITED STATES PATENT OFFICEJOHN A. POTTER, 0F MOORES,

TRIC & MANUFACTURING HEAT EXCHANGER Application led .Tune 30, 1930.Serial No. 464,922.

My invention relates to tubular heat exchangers of the multi-pass typehaving a of the passes and it has for an object to provide apparatus of'.ihis character having a removable tube bundle and a removable bafllewith improved sealing means for the baffle;

My invention has for a further objectto provide sealing means for thebaille which .vill effect a fluid-tight joint between the baille and theshell of the heat exchanger but which, at the same time, will notinterfere with the freedom of removal of the baille and the tube bundlefrom the shell.

In my copending application, Serial No. 463,123, entitled Heatexchanger, and assigned to the Vestinghouse Electric & ManufacturingCompany, I disclose and claim a form of heat exchanger having a shellwith .L tube bundle and a baffle disposed interiorly of the shell andarranged to be readily removable therefrom. In the embodiment, theredisclosed, I effect a substantially fluid- .tight joint between thebaille and the shell with an improved form of sealing structure whichdoes not interfere with the freedom of removal of the tube bundle andthe baille from the shell. j

In thepresent application, I show a struc- ',ure for effecting a sealbetween the baille and the shell, which structure is arranged inaccordance with the principles set forth in the aforesaid application,but which is of a more simplified form and less expensive to construct.As shown in the present application, the sealing structure embodies, inits preferred forni, a strip at the lateral edges of the baille andarranged to directly engage the interior surface of the shell. Inanother form, the strip may be secured to the interior of the shell soas to directly engage 011e side of the lateral marginal portions of thebaille. While the strip employed in this embodiment may be of one layer,or in other words a single element, I prefer to utilize a laminatedstrip composed of a plurality of relatively thin elements which arearranged to form a seal in the nature of a labyrinth. The element orelements are sufficiently flexble to permit them to be held in sealingengagement in response to fluid pressure. In addition, in the presentembodiment, I disclose an improved form of interior baille structure forcompelling the fluid to more I A further object of my invention is to.

form these strips with sulicient flexibility to permit the differentialpressure existing on opposite sides of the baffle to press the freeedges of the strips into continuous and substantially fluid-tightengagement4 with the f shell or the baille.

A still further object of my invention is to provide a. substantiallyfluid-tight joint, in apparatus of the type designated, which includesadjacent substantially co-extensive abutment surfaces and a plurality ofstrips fixed along one of the abutment surfaces and responsive to iuidpressure toengage the adjacent abutment surface.

A still further object of my invention is to provide, in the type ofjoint designated, a flexible sealing strip secured along one of theabutment surfaces, presenting a plurality of narrow lines of contactwith the adjacent abutment surface.

Still another object of my invention is to provide improved baffle meansfor causing the fluid to more completely traverse the full length of theshell.

These and other objects are effected by my invention, as will beapparent from the following description and claims taken in connectionwith the accompanying drawing forming a partof this application, inwhich:

Fig. 1 is a view, in sectional elevation, of one form of heat exchangerarranged 1n accordance with my invention;

Fig. 2 is a horizontal plan view taken of the arrangement shown in Figs.l1 to 4,

vshowing the sealing strip fixed to the shell instead of the baffle;and, y

Fig. 'G is a detail view of another modification of the.arrangement,shown in Figs. l

to 4, showing the sealing strip supported :at its center and free atboth edges.

Referring now to the drawing, I show, in Fig. 1, a heat exchangerembodying a shell 11 having-.secured thereto flanges 12 and 13 andhaving located, near one end lthereof, an in let connection 14 and an0ppositely-disposed outlet yconnection l5 for circulating a fluid mediumthrough the shell. A tube bundle 16 is longitudinally disposed withinthe shell and is supported, at one .if its ends, in a ystationary tubeplate 17 secured to the flangeV 12, and is supported at the other. ofits ends in a floating tube `plate 18. A cover member 19, having aninlet connection 20, an oppositely-disposed l outlet connection 21 and apartition 22, cooperates with the tube plate 17 to. provide an upperinlet box or chamber 23 for directing a fluid into Ythe upper portion ofthe tube bundle and a lower box or chamber 4 for receiving the fluidfrom the'lower portion of the tube bundle. The cover 19 is removablysecured to the tube plate 17 to provide access to the tubes.

A bonnet member 25 cooperates with the floating tube plate 18-to directthe fluid.

from the upper portion of the tube bundle back through the lowerportion. The bonnet member 25 is securedv at its periphery with afluid-tight jointv to `.tube plate 18.

A removable hood member 26 is secured tothe flange 13 and encloses thebonnet member 25 and the floating tube plate 18.

The tube plate 18 and the bonnet member 25 are so arranged that they fitloosely at iheir' peripheral portions in the interiorof the shell andhood member., which permits them to float back and forth to allow forrelative expansion and contraction of the tube bundle with respect tothe shell.

. A longitudinal baille plate 27, is disposed .l interiorly `of'th'etube bundle 16 between the inletV ltand the outlet 15 and arranged to'extend longitudinallyl of the shell for dividing the interior thereofinto two passes or compartments, an upper pass 28 and a cent transverselower pass 29. The longitudinal baflle 27 is secured at one end to thetube late 17 by any suitable means, such as wel ing, and is baille 27 inpairs in diametrically-opposed position. They are secured at their inneredges to the longitudinal baille 27 by any suitable means, such aswelding. At their outer edges they are held in the desired position bylongitudinal stay-bolts 34 and spacers-35. The stay-bolts are secured inthe tube plate 17 and extend longitudinally through the transversebaffles. The spacers 35 surround the. stay-bolts with their ends inengagement with the sides of the adjabaflles. The transverse baffles areprovided with openings 33, the openings in alternate `baffles beingstaggered with respect 4to the openings in the remaining baflles so asto produce a zig-zag flow of the fluid' as shown by the arrows. Thetubes of the tube bundle 16, which are shown in broken outline in Fig.1, pass through holes provided therefor in the transverse baflles andmay be grouped somewhat as shown in Fig. 3.

` Supplementary longitudinal baffles 36 are provided in each of thepasses, in the first pass 28 facing the inlet 14 and in the second pass29 facing the outlet 15.' Each of these 'extend between the tube plate17 -and the first transverse baille 32. However, openings 37 areprovided in the ends of the supplementary baflles which abutl againstthe .tube plate 17 whereby the fluid is compelled to traverse the ,fulllength of the tube bundle in each of the asses.

The path o -flow of one fluid through vthe tubes of the tube bundle andthe path of flow of another fluid through the interior of the shell willnow be apparent from the foregomgdescription. In addition, it

will be observed that the tubebundle and the entire baille structure aretied together as a single assembly and are removably se- .cured as aunit in the shell by means of the 'tube plate 17.I The tube plate 18,the bonnet slrip 41 and a retaining strip 42 both secured, preferably,on the side of' the baffle subjected to higher fluid pressure, that is,the inlet side of the baille. rl`he sealing strip ll and the retainingstrip 42 may be secured at their ends to the baffle by means of rivets43. Intermediate of their ends, they are held in position on the marginof the baffle by the'edges of suitable slots or recesses 44 provided atthe junction of the periphery of the transverse baffles 32 and theAlongitudinal baffle 27. By retaining the strips in position upon thebaffle in this manner, they may be readily removed therefrom merely bycutting the rivets 43 holding them at each end. The retaining strip 42besides holding the fixed edge of the sealing strips firmly against thebaffle provides, also, a protecting guard over the laminations of thesealing trip so asto minimize the damage in handling.

rlhe laminations of the sealing strips 41 are made of yieldable orflexible material which is of such relatively small thickness hat, whenin position to contact with the interior of the shell structure at asuitable angle, any very small pressure difference existing between thefluid flowing in the first and secondpasses of the shell, as caused 'iythe resistance of the tube bundle and baffle elements, compels the freeedges of the sealing strips 41 to be pressed into engagement with theadjacent portions of ,the shell. One of the outstanding advantages ofsuch .n arrangement, resides in the factthat the laminations may havesuch flexibility that they readily conform with any surfaceirregularities obtaining in the engaged surface of the shell resultingfrom commercial manu- "acture I prefer to make the sealing strip 4l ofa. plurality of laminations so that the edges of "the individuallamina-tions form a plurality of lines contacts with the interior sur-.'ace of lthe shell. Each lamination is so `arranged that it is free toassume its own sealing position without interference 'from theotherlaminations. In thismanner, somewhat of the labyrinth type of seal isformed, that is, a plurality of lines of sealing engagement arranged inseries. It is to be understood that, while I use a strip of a pluralityof laminations, or, in other words, a plurality of thin strips arrangedin sealing ent gagement, I l"may use a sealing strip comprising only onelamination. y I may also use a sealing strip having the fixededge-thereof formed as a solid strip while the free edge r the edge incontact with the interior of the shell is yformed of a plurality ofrelatively thin webportions such as would be obtained Aby cuttinglongitudinal recesses in the free edge ofethe strip, thus having essen-.ially a plurality of single strips forming a plurality of lines ofsealing engagement with the interior of the shell.

The sealing strip 41 may be biased toward a horizontal position so that,when raised to an inclined position at the timey of insertion of thebaffle 27 into the shell 11, the laminations engage the shell with aspring tension. However, the pressure exerted upon the laminations bythe higher fluid pressure existing on that side of the baffle is mainlyrelied upon for pressing the free edges of the laminations intocontinuous engagement with the adjacent portion of the interioi surfaceofthe shell.

In Fig. 5, I show 'another form of seal embodying my invention in whichthe laminated sealing strips 4l, instead of being attached ,to theremovable baille 27, are attached to the interior of the shell. Thesealing strips are secured to the shell in a position above thelongitudinal baffle 27, or on the side thereof exposed to the higherpressure.. The upper edge of the sealing strips are made fast to theshell while the lower edge is free to be flexed or pressed intoengagement with the longitudinal bafile 27 in. response to the higherfluid pressure existing above the baille. The strip 42 is secured overthe sealing strips 41 to retain the fixed edge in position and toprovide a protecting guard over portions of the sealing strlps.

' Referring now to Fig. 6, I show a detail view of still another form ofseal embodying my invention in which the laminated sealing strip 4l issecured substantially midway between its edges to the transverse baffles32, and is free at both of its edges to engage, at one edge, theinterior surface of the shell 1l and, at the other edge, the upper sideof the baffle 27 in response to the fluid pressure difference onopposite sides of the baffle. In this embodiment the sealing strip 41,the retaining strips 40 and 42 are secured to a bracket 45 by means ofrivets 43. The retaining strips 40 and 42 are placed on opposite sidesof the sealing strip 41 and are spaced away from the edge thereofsufficiently to allow the latter to maintain the desired flexibility.The bracket 45 which is above the sealing strip is in turn secured tothe transverse baille 32 by means of a. rivet 46. I may place thebracket 45below the sealing strip and secure it to the shell 1l ormodify it in any other suitable manner that Will permit it to be securedto the shell 11 instead of the transverse baffle 321 The bracket 45 maybe fitted-loosely about the rivet 46 for allowing the sealing strip tohave a limited transverse and side-to-side movement for the purpose ofpermitting the flexible edges thereof to find their engaging positionfreely in response to fluid pressure.

In all embodiments, I\prefer`, according to my invention, to make therelatively -thin llll ` inlet and outlet the spirit thereof,

forming the plurality of lines'of seal, of the i Arequired strength andof sufficient flexibilityr to permit' it to `bend under fiuid pressure.

While in the embodiments of my invention illustrated and described,'Ihave' used sealingstrips on the side of the bafiie exposed to the higherpressure, it is to be understood that my invention is not confined' tousing the sealing strips on this side only. y

Also, While I have shown 'my invention in three forms, it will beobvious to those skilled'in the art that it is not so limited,

but is susceptible of various other changes and modifications, withoutdeparting from and I desire, therefore, that only such limitations shallbe placed thereupon as arevimposed by the prior art or asare'specifically set forth in the appended claims.

What I claim is:

1. In heat exchange apparatus, the combination of a shell, a removabletube bundle disposed in the shell, a removable baffle disposed in theshell and dividing the latter into first and second compartments, fluidmeans provided in the shell and arranged to circulate the iuid throughthe compartments in series, and a flexible strip fitted directly'betweenthe inner wall of the shell and the baffle and responsive to fluidpressure for effecting a substantially flllllild-tight joint between thebafiie 'and the s e Y 2. -In heat exchange apparatus, the ,combinationof a shell, a removable tube bundle y disposed in the shell, a removablebaflie disposed in the shell and dividing the latter ind arranged tocirculate the fluid throufrh the compartments in series, and a stripformed on a marginal portion of the baffle and having a flexible edgeportion directly `engaging. the interior'surface of the shell, saidfiexible edge portion being retained in fiuid-ti ht engagement with:

- the shell by the fluid substantially the interior surface o pressuredifference vexisting on opposite sides of the vbaliie.

.ter into first and second compartments, fiuid.

inlet and outlet means provided in the. shell rated in the tube bundlestructure into first and second compartments, fiuid -inlet and outletmeans provided in the shell the shell and having a flexible edge portionengaging the baffle, said flexibleedge portion being retained insubstantially fiuidtight engagement with'the baffle bythe fluid pressuredifference existing'on opposite sides of the baffle.

4. In heat exchange apparatus, the vcombination of a shell structure, aremovable tube bundle structure disposed within the shell structure, aremovablebafile incorpoviding the interior ofthe shell structure intofirst and second compartments, fluid inlet and `outlet means provided inthe shell structure and arranged to circulate fiuid through thecompartments in series, a strip having oppositely-disposed fiexiblemarginal portions, one of the marginal portions e119'.

gaging the baflie and the other of the marginal portionsengaging thevinterior surface of the shell, and means to secure the stripintermediate the marginal portions thereof to the tube bundle structure,said flexible marginal ortions being retained in substantially fiui-tight engagement with both the baiiie and the interior surfacev of theshell by the fluidpressure difference existing on opposite sides of thebafile... c a heat exchanger l5. The combination with including a shellelement .and 4a bale element dividing the interior space of the shellelement `into first and second passes, of laminated. flexible elementsresponsive to the pressure difference existing betweenthe first andsecond passes' for'forming a plurality of lines of seal between thelateral l marginal portions of the' baffle element and the shellelement.

6. A heat exchange apparatus as' claimed in claim 5in which thelaminated fiexible elements are composed of a corrosive-resistantmaterial. A

7. The combination with a heat exchanger including a-shell velement4 anda removable baffle element dividin the interior space of the shellelement into rst and second passes, of flexible metallic strip meanscarrled by one of said elements and cooperating with. l

the othelgelement to effect a plurality of narrow-lines of'seal inresponse to pressure .,difference existing between the `iirst and'second passes.

8.A heat exchange apparatus as claimed in claim 7 in which the laminatedexible strip is composed of a corrosive-resistant metal.

9. In a heat exchanger, in combination, a`- shell, a tube `bundle andbaille removably supported in the shell, the inner. wall surface of theshell and the lateral marginal ortions of the bafile providingco-extending abutment surfaces,I and sealing means coopros ' intoerating with the abutment surfaces for forming a substantiallyfluid-tight joint between the baille and the shell, said sealing means.including a flexed strip secured along one of said abutment surfaceskand retained in en'- gagement 4with the other of said abutment surfacespartly in response to spring tenslon existing in the stri and partly inresponse to the differential uid pressure existing on opposite sides ofthe baille.

10. In a heat exchanger, in combination, a shell, a tube bundle andbaflle removably supported in the shell, the inner wall surface of theshell and the lateral marginal portions of the baffle providinco-extending abutment surfaces, and sea ing means cooperating with theabutment surfaces to form a substantially fluid-tight joint between`thebaffle and the shell, said sealing means including flexible laminatedstrips secured along one of said abutment surfaces and retained insubstantially fluid-tight engagement with the other of said` abutmentsurfaces in response to the differential fluid pressure exhausting onopposite sides of the baille.

11. In heat exchange apparatus, the combination of a shell, a removabletube bundle disposed within the shell, and embodyin a removable bafflemember, said baffle mem er having a ortion thereof arranged' to form ajoint wit a portion of the interior surface of the shell, said jointincluding a plurality of strips of flexible sheet material each securedto one of the portions and each responsive to fluid pressure in onedirection for engaging the other portion, and said joint also includinga stri of relatively rigid sheet material secure to one of the portionsin a position to embrace the fiexible strips.

12. In heat exchange apparatus, the combination of a shell, a tubebundle, means for supportin the tube bundle within the shell and proviing for removal thereof fromthe shell, longitudinally-extending. andtransversely-extending baffles incorporated in the tube'bundle andremovable therewith from the shell, a plurality of flexible stripssecured to the lateral edges of one side of the longitudinal baffle,means responsive to fluid ressure in the shell for retamin the flexilestrips in engagement with t e interior surface of the shell to effect asubstantially fluid-tight joint between the longitudinal baffle and theshell, and means including slots formed in the transverse baffles forsecuring the flexible strips in position on the longitudinal baille. l

-13. In heat exchange apparatus, the combination of a shell, a removabletube bundle disposed within the shell and embod a removable baillemember, said baffle mem r arr d to divide the interior of the shellandsecondpasses, fluid inlet and outlet means provided in the shell andarranged for circulating a fiuid through the passes in series, wherebythe average fluid pressure obtaining inthe first pass is relativelyhigher than the average fluid pressure obtaining in the second pass, andmeans for effecting a substantially fluid-tight joint between themarginal portions of the baffle and the adjacent portion of the interiorsurface of the shell, said joint including a plurality of flexiblemembers secured at one of their edges along the marginal portions of theside of the baiile exposed to the higher fluid pressure and having theirother Vedges held in sealing engagement with the interior surface of theshell by the fluid pressuie difference obtaining between the passes.

14. In heat exchange apparatus, the combination of a shell, a tubebundle structure, means for supporting the tube bundle Structure withinthe shell and providing for removal thereof from the shell, alongitudinally-extending baffle and a plurality oftransversely-extending bafiles incorporated in the tube bundlestructure, and a flexible strip for effecting a substantiallyfluid-tight joint between the longitudinal baffle and the shell, saidtransverse baffles cooperating with the longitudinal baflle to retain anedge of the flexible strip in Vfixed position upon the latter.

15. In heat exchange apparatus, the combination of a shell, a tubebundle, means for supporting the tube bundle in the shell and providingfor removal thereof from the shell, a baffle extending longitudinallywithin the shell and removable therefrom with the tube bundle, saidbaille being arranged to divide, the shell into first and second passes,means for effecting alsubstantially Huid-tight seal between the baffleand the interior of the shell, said joint including a plurality offlexible strips extending longitudinally of' the shell in the firstpass, and means for securing said strips at one of their edges to theinterior surface of the shell and providing for engagement of the otheredges of the strips with the baffle in response to the fluid pressuredifference existing between the asses.

In testimony whereof, I have ereunto `subscribed my name this 26th dayof June,

JOHN A.. POTTER.

